Any homeowner knows that a lot of free time goes into taking care of your house. But what if your house could take care of you? That's the dream of the "smart home," and while there's no true sci-fi intelligent homes that can do everything you need, we're getting closer.

Every day, an average 5.5 million smart devices are being connected in homes around the world, according to research firm Gartner. It further estimates there will be 6.4 billion of these "Internet of Things" devices by year's end, and 20.8 billion IoT devices by 2020. If you want to get in on the ground floor, here are some gadgets you can buy today.

1. Tech to help you sleep better

There's been an explosion of gadgets that are designed to monitor your sleep and help you improve it. The market for these gadgets is headed for more than $125 million in 2017.

Sense ($129), for example, is a little orb that sits in your room monitoring noise, light, temperature, humidity and air particles, and can wake you up at the ideal part of your sleep cycle. A tiny clip attached to your pillow tracks your movements. In the morning, it can tell you through an Apple app how much sleep you really got, and if something in your environment is disturbing your rest.

These products mostly stand alone, but an upcoming sensor from Samsung called SleepSense will link up with Samsung's SmartThings Hub. When SleepSense detects that you're asleep it will turn off the lights and TV, and crank up the A/C. When you wake up, it'll turn on the coffee maker.

How many times have you come home later than expected? It's dark outside and, of course, you didn't leave the lights on at home. You struggle to get the key in the door and, once you open it, you have to feel around the wall for the light switch. Then, room by dark room, you repeat those steps.

Wouldn't it be easier to tap an app on your phone while you're still in your car and turn on all the lights? That's possible right now.

Lightbulb makers sell bulbs that you can link to the rest of your smart house. For example, with Philips' Hue LED lights and Philips Hue Bridge ($60; Amazon affiliate link) smart home device, you can remotely turn on and turn off dozens of lightbulbs in and around your house.

These lights are also dimmable, so you can have softer lighting at night, or your lights can gently wake you up by slowly turning on in the morning. You can even sync your lightbulbs to your streaming music or movies. Say you turn on Netflix, your Philips lightbulbs can be programmed to automatically dim, for optimal viewing.

Bonus: "Hey, Siri. Turn on the lights." You can connect your Philips Hue lightbulbs to Apple's IoT hub, the Apple HomeKit. With it, you can use Apple's voice-activated assistant, Siri, to turn on or turn off your lights with voice commands.

3. A smart lock for your smart home

If you've got a connected car, you may already be remotely turning it on or unlocking your doors without even touching your key ring. Cars are increasingly equipped with Internet-connected technology, so you can do things like unlock the doors when you've got an armful of groceries.

The same concept is at work in IoT homes. For instance, you can remotely lock and unlock your doors. Smart locks, like Kwikset's Kevo ($160; Amazon link) are Bluetooth-connected, too.

With Kevo and its smartphone app, you can program your home locks, so only your family members can unlock the doors. You can set the times of day when they can unlock the doors, and you can give your house guests temporary access to your home. No keys required.

Once your family, guests and you have downloaded the Kevo app to your smartphone, you don't even need to take it out of your pocket or purse for it to unlock your doors. Just touch the lock with your finger, and it'll unlock.

4. Keeping things fresh

If you roll your eyes at the idea of smart appliances like a smart refrigerator, that's understandable. Why would you need a fridge that connects to the Internet? However, there are actually a few good reasons.

LG, for example, has SmartDiagnosis. If your LG smart appliance is on the fritz, it will connect you with LG's customer service department by phone, or with a smartphone app. The repair techs can tell you what's wrong with it, and help you get it fixed fast.

Then there's food tracking. You can get alerts you when you need to restock an item, or when an item is about to expire. Samsung's upcoming Family Hub refrigerator even has cameras inside, so you can remotely check what's on its shelves while you're out grocery shopping.

5. A house that cleans itself

If you've ever been vacuuming and wished you had Rosie from the Jetsons around to help out, you can stop your wishing. Roomba made its name with robotic vacuums that keep your house clean without you lifting a finger. However, its latest model is the smartest yet.

The Roomba 980 ($899) has a Wi-Fi connection so it can connect to your network. That lets you control it with a smartphone app no matter where you are. You can remotely tell Roomba to start vacuuming, and on its dashboard, you can see what Roomba has been doing while you were out.

Plus, the 980 fixes one of Roomba's most frustrating faults. If you've ever used a Roomba, or another robotic vacuum, you can watch it clean and clean one section of your house, and continually miss a spot. That's frustrating, but it's fixed. Now, Roomba creates a map of the room it's cleaning, using its cameras and sensors, so it knows if it hasn't covered everything.

Bonus: Prepare for the future

One of the biggest hurdles to a true smart home is that most gadgets stand alone or only work with gadgets from the same company. That's why smart home hubs are going to be important.

Instead of tapping an app to unlock your door, then another app to put on your lights, and yet another app to turn off your home security system, you just do all that from a single spot. There are plenty of companies pushing their own hubs.

However, be sure to do your research on what gadgets will and won't connect before you commit to one. Apple's HomeKit, for example, works with non-Apple gadgets, but only if they're HomeKit compatible. Some gadgets you buy now might not be. There are also companies like Cassia and HomeGenie that are creating third-party hubs and software that try to work with everything, but may not be fully compatible.

Whatever you choose, just keep in mind that it's still the early days of the smart gadget revolution. So, enjoy what they can do, but don't be too surprised if everything changes in a year or two.

On the Kim Komando Show, the nation's largest weekend radio talk show, Kim takes calls and dispenses advice on today's digital lifestyle, from smartphones and tablets to online privacy and data hacks. For her daily tips, free newsletters and more, visit her website at Komando.com. Email her at techcomments@usatoday.com.